Question

If you put a ballon in the freezer, what happens to the gas pressure in the ballon?

Answer 1

The volume will decrease. The energy of the gas molecules is directly related to the temperature. When the temperature drops, the energy of the molecules drops. When the molecules have less energy, they hit the walls of the balloon less often and with less force. This actually lowers the pressure inside the balloon. Since the outside pressure is still the same, it will push in on the balloon and decrease the volume of the balloon until the pressure is equal inside and outside. So, lowering the temperature while keeping the pressure constant, will eventually lower the volume of the gas.